A SCIENTIST has documented the death of 10,000ha of mangroves along the Queensland and Northern Territory coastlines, citing climate change as the likely culprit.

Mangroves expert Dr Norm Duke feared the destruction could hold further implications for the wider ecosystem.

He said the mangrove forests might never recover.

Dr Duke recorded the dead trees during a 200km flight over the coastline last month.

He told the ABC he had never seen mangrove destruction on such a scale, and coral bleaching and El Nino weather conditions were probably to blame.

"Certainly nothing in my experience had prepared me to see images like that," he said.

Mangroves are a vital component of healthy waterways and serve as breeding grounds for fish, crabs, prawns and other species.

Dr Duke's findings followed the discovery this week of an extinct kelp forest along 100km of Western Australia's coastline.

University of Western Australia researchers attributed the widespread ruin to an unprecedented heatwave in 2011 that allowed algae, tropical and subtropical fish, seaweed and coral to increase rapidly.

They said there had been no sign of recovery five years later and it appeared the former forest was totally extinct.